香蕉植株内生细菌群落多态性研究

采用平板法对香蕉(Musa nana)植株的内生细菌进行分离纯化,并采用细菌脂肪酸法进行鉴定。结果表明,从香蕉的健康植株和感病植株中共分离得到内生细菌21属24种。从健株分离得到9种内生细菌,其中根、茎和叶分别分离到6种、2种和8种内生细菌。从病株分离得到15属17种内生细菌,其中根、茎和叶分别分离到3种、11种和6种。香蕉健株根部的内生细菌含量最高,达5.195×106cfu g-1,下部叶片内生细菌的含量最低,仅为30 cfu g-1;香蕉病株茎部内生细菌的数量显著高于其他部位,达1.05×107cfu g-1。这说明香蕉在不同生长状态下,其内生细菌的种类和数量存在多样性。

基于16S rDNA测序研究新西兰兔腹腔镜探查术后腹腔微生物群落多态性改变

目的利用细菌16S核糖体DNA(16S rDNA)测序技术,研究使用便携式腹腔镜进行腹腔探查术后腹腔中微生物群落多态性的变化情况。方法将新西兰兔分为模型组及对照组。模型组兔使用便携式腹腔镜进行探查手术,对照组兔不做任何处理。一周后,取模型组和对照组的腹腔积液,进行16S rDNA测序,分析微生物群落多态性,探究腹腔积液的微生物群落变化情况。结果针对测序结果,采用生物信息学和组间差异分析,发现两组的微生物群落相似度良好。OTU分类学分析及物种组成成分分析(丰度-均匀度曲线和Venn图)发现,模型组相对于对照组,在微生物群落水平上有显著升高。α多样性分析(Sobs、Ace、Shannon、Simpson)显示,模型组在微生物群落丰富度和多样性方面均高于对照组。微生物组成成份分析显示,模型组较对照组杂菌数量占比增加约30%。对两组样本物种差异进行显著性检验,发现巴斯德菌、奈瑟菌、冢村菌的比例有显著升高。结论新西兰兔在腹腔镜行腹腔探查术后,腹腔积液中微生物群落数量上升,且以巴斯德菌、奈瑟菌、冢村菌升高最为明显。

应用RFLP和DGGE技术对沼气池中产甲烷菌多样性的研究

利用PCR-RFLP和PCR-DGGE技术对处于正常运行阶段的4口农村户用沼气池进行研究,考查其中产甲烷菌的种群结构并对其进行系统发育分析。特异性地扩增产甲烷菌mcrA片段和16S rDNA序列分别进行RFLP分析和DGGE分析。对RFLP得到的每一个独特的OTU(operational taxonomic units)和DGGE中的优势条带进行测序及序列分析。结果表明,不同发酵原料的沼气池中产甲烷菌的优势类群存在差异性,但又有一定的相似性。同时研究结果显示,2种不同实验方法得出的结论有着某些一致性。

泥土微生物检验及其在法庭科学中的应用

泥土物证的检验一向归属于微量物证的检验范畴,但随着生物技术的发展和方法的成熟,近年来越来越多的法庭科学工作者开始关注泥土中微生物物证的检验分析。泥土是微生物的大本营,其中蕴含着极为丰富的微生物信息,这些微生物的种类和数量可以反映泥土的很多特征,如可能的来源区域及其气候特点与土地利用方式等。泥土微生物检验是一个新兴的物证研究方向,具有极大的应用潜力,集成有信息量巨大、区分精度高、检验所需样品量少等优点。通过泥土微生物的比对分析或来源推断,可为某些疑难案件侦破提供方向、线索或证据。本文就泥土微生物物证的特点、研究方法、应用价值等方面进行综述,并提出需要解决的问题,以期为进一步深入研究应用泥土微生物辅助破案提供借鉴与参考。

Seasonal dynamics of wintering waterbirds in two shallow lakes along Yangtze River in Anhui Province

The shallow lake wetlands in the middle and lower Yangtze River floodplain are important wintering and stopover habitats for migratory waterbirds on the East Asia-Australia Flyway.With increasing fishery practices in recent years,however,the wetlands have deteriorated significantly and now threaten wintering waterbirds.To gain insight into the influence of deteriorating wetlands on waterbirds,we conducted a survey of wintering waterbird species,population size,and distribution across 11 belt transects in Caizi Lake and Shengjin Lake,two shallow lakes along the Yangtze River in Anhui Province from November 2007-April 2008 and from November 2008-April 2009,respectively.The impacts of different fishery patterns on the distribution of waterbirds were also analyzed.A total of 43 waterbirds species belong to 7 orders of 12 families were counted during the surveys,of which 38 were found in Caizi Lake with a density of 8.2 ind./hm2,and 42 in Shengjin Lake with a density of 3.5 ind./hm2.Geese（Anser cygnoides）,bean geese（Anser fabalis）,tundra swan（Cygnus columbianus）,and dunlin（Calidris alpina） were the dominant species in the two shallow lakes.Species number and individual assemble reached maximum at the end of December and in early January of the following year,without coincidence of the largest flock for different ecological groups.Based on waterbird diversity across the 11 belt transects and the fishery patterns,habitats could be divided into three groups.Gruiformes,Anseriformes and Charadriiformes had relatively higher densities in the natural fishery zones and lower densities in the cage fishery zones;whereas,the density of Ardeidae showed little change across all lake zones.It is important to develop sustainable fishery patterns in shallow lakes along the middle and lower Yangtze River floodplain to better protect resources of wintering waterbirds.

Diversity of Sucking Lice on Small Mammals in the Surrounding Areas of Erhai Lake in Yunnan,China

An investigation of sucking lice on the body surface of small mammals was carried out in the surrounding areas of Erhai Lake in Dali, Yunnan from 2003 to 2004. From investigation sites, 3 303 small mammal hosts were captured and identified into 7 families, 15 genera and 21 species in 4 orders （Rodentia, Insectivora, Scandentia and Carnivora）, while t4 635 individuals of sucking lice collected from the body surface of the small mammal hosts are identified into 5 families, 6 genera and 21 species in the Order Anoplura, The sites stand alongside three cordilleras surrounding the Erhai Lake, namely Eastern Wuliang Mountain, Southern Ailao Mountain and Western Cangshan Mountain. The three confined oriented areas are different landscapes within the same zone where the longitude, latitude, altitude and fauna are homologous but isolated by Erhai Lake as inartificial barrier. The aim of this study was to recognize features of the species diversity, abundance, community structure, similarity and distribution of sucking lice in different landscapes within the same zone. The results showed the species diversity of sucking lice was very low with a very simple community structure. The distribution of sucking lice and their corresponding hosts are quite uneven among different oriented areas and this may imply that ecological environment influences the species composition and distribution of sucking lice and their corresponding hosts. A certain species of hosts usually have their fixed louse species. The similarity of sucking louse communities is highly consistent with the affinity of small mammal hosts in taxonomy. Species of sucking lice on the same small mammal host in different oriented areas of Erhai Lake are homologous. The results strongly suggest a close relationship of co-evolution between sucking lice and their hosts.

Advances in Research on the Structure and Diversity Variation of Insect Communities in Wetland

The species diversity, structure and dynamic rules of insect communities in wetland can provide data of the insects for the protection, utilization and monitor- ing of wetland, which is an essential link to maintain the healthy ecological system of the wetland and protect the biodiversity in the wetland. A systematic study on the composition and succession of insect communities in the wetland, as well as the indication of insect groups can provide a theoretical basis for wetland protection and management, and thus promote the development of regional economy and en- vironmental protection.

Bacterial diversity in surface water of the Yellow Sea during and after a green alga tide in 2008

From May to August 2008, a large "green tide", consisting of the alga Ulva (Enteromorpha) prolifera, occurred in the Yellow Sea, China, affecting the local marine ecosystem and human activities. We investigated the influence of the green tide on the microbial community in the surface seawater, at four sites from July to August 2008, using bacterial 16S rRNA gene clone libraries. We sequenced 228 clones of unique patterns identified by restriction fragment length polymorphism (RFLP) techniques. The results show that 228 sequenced clones fell into six bacterial phyla:Proteobacteria, Bacteroidetes, Cyanobacteria, Verrucomicrobia, Actinobacteria, and Planctomycetes. Alphaproteobacteria (33%), Gammaproteobacteria (25%), Bacteroidetes (23%) and Cyanobacteria (9%) dominated the assemblage. Comparison between samples collected in July (during the tide) and those collected in August (after the tide) showed that, in the microbial community, diversities of Alphaproteobacteria and Cyanobacteria increased after the tide, while those of Gammaproteobacteria and Bacteroidetes decreased. These results indicate that the green tide influenced the growth of some bacteria, and provide information for further studies on the interactions and relationships between U. prolifera and the bacterial community. This study suggests that microbial community analysis is a good approach to monitoring green tides.

Understory flora and community physiognomy of planted forests in the degraded purple soil ecosystem, South China

The flora and community physiognomy of degraded plantation ecosystems onpurple soil were investigated in Ninghua County of Fujian Province, China to understand therelationship between plant diversity and ecosystem processes.. Four different restorationcommunities (labeled as ecological restoration treatment Ⅰ, Ⅱ, Ⅲ and Ⅳ) were selected byspace-time replacement method according to the erosion intensity in degraded purple soil ecosystem.The results showed that there were totally 86 plant species belonging to 78 genera and 43 familiesin the degraded purple soil ecosystem. Of the 15 types of distribution area in spermatophyte genus,12 types were found in the purple soil ecosystem. Along restoration gradient from low to high, plantgrowth type and life form spectra became abundant more and more, and the spermatophyte genera foreach distribution area type and genera numbers for different foliage characters increased as well.It is concluded that the plant flora and physiognomy in ecological restoration process become morecomplex and diverse, indicating that the forest ecosystem on purple soil tends to be more stable.

Survey of Plant Community Characteristics in Bamenwan Mangrove of Wenchang City

According to natural conditions and vegetation distribution characteristics of Wenchang Bamenwan Mangrove Forest, sample plots were set up to investigate plant community characteristics in this area, and to explore the diversity characteristics of different subareas and calculate importance values of various tree species in the study area. According to the investigation, there are 48 plant species of 42 genera and 28 families in Bamenwan Mangrove Forest, including 29 tree species of 24 genera and 17 families. Among the tree species, those on the top 5 in the importance value list are Hibiscus tiliaceus, Bruguiera sexangula, Lumnitzera littorea, Rhizophora apiculata, Xylocarpus granatum. There are 3 shrub species of 3 genera and 3 families, including Atalantia buxifolia, Lantana camara and Streblus asper. And there are 16 herbal species of 16 genera and 11 families, including Acrostichum aureum, Vernonia cinerea, Acanthus ilicifolius, Alocasia macrorrhiza, Synedrel a nodiflora, Gynura japonica and etc.. Diversity of the mangrove in different areas varies greatly, Shannon-Wiener index and richness index of semi-mangrove forest are both higher than those of other 3 mangrove forests. Bamenwan Mangrove Forest is characterized by diversified species and complex structures, but the community diversity is unevenly distributed because of the interventions from many factors. More human efforts are suggested to enhance the mangrove protection, so as to enrich the community diversity.

A comparable study of microbial community in aerobic granular sludge and activated sludge for wastewater treatment

Effect of ammonia at different concentrations on aerobic granular sludge and activated sludge was investigated in this study. Meanwhile, bacterial diversity variation and ammonia oxidizing bacterium （AOB） quantification within both kinds of sludge were monitored by terminal restriction fragment length polymorphism （T-RFLP） and real-time PCR （RT-PCR） technique, respectively. The results showed that the COD removal of both kinds of sludge changed slightly when the ammonia removal efficiency decreased gradually with the ammonia concentration increased from 100 mg L^-1 to 500 mg L^-1 Furthermore, activated sludge demonstrated higher ammonia removal ability than that of aerobic granular sludge （10%- 16%）. As revealed by T-RFLP, activated sludge was of higher ammonia removal ability and more abounding bacterial diversity than that of aerobic granular sludge, suggesting that the bacterial diversity was probably relevant to the ammonia removal. The RT-PCR results indicated that the AOB population size of activated sludge and aerobic granular sludge were 2.80× 10^4-3.44× 10^4cells （g dried sludge）^-1 and 7.83×10^4-1.18×10^5cells （g dried sludge）^-1, respectively. There is no obvious positive correlation between the ammonia removal ability and number of AOB in both kinds of sludge.